Homes that Take 1st Place with Grade 1

NGBS coverThe ICC/ASHRAE 700-2015 National Green Building Standard (NGBS) was released in March. This post is the fifth in a series of eight that will examine what’s different in this new edition – and what’s changed in the world of sustainable construction since the 2012 NGBS. This week: Updates to Energy Efficiency.

With the newest edition of the standard, there have been substantial revisions to the Energy Efficiency category. All installation of insulation is now required to meet Grade 1 requirements. Other grades are no longer acceptable, and Grade 1 installation must be verified onsite by a third-party inspector before drywall goes up.

Rating levels have also become more stringent, with the 2015 International Energy Conservation Code (IECC) the new baseline for the prescriptive path, as well as for calculating whole-building energy savings within the performance path.

energy efficiency requirementsThe updated standard also now offers more pathways for proving compliance with energy efficiency requirements, as listed here: Click on the table (left) to enlarge it.

Other updates in this category include:

  • Multifamily buildings have additional notations and sections for complying with energy efficiency conformance requirements. This allows the NGBS to be applied more accurately to both single-family and multifamily buildings.
  • The prescriptive path has a number of new mandates, such as setting a maximum total building UA, prescriptive R-value and fenestration requirements, and duct testing in accordance with 2015 IECC.
  • Dynamic glazing can now be used to satisfy the Solar Heat Gain Coefficient requirements.
  • The “HVAC Equipment Efficiency” section better addresses homes with multiple heating and cooling systems.
  • Sections pertaining to lighting controls are updated to separate indoor, outdoor and common areas, as well as increase the required minimum percentage of dimmable controls or occupancy sensors from 25% to 50% of lighting fixtures for any points to be awarded.
  • Point are available for installation of potable hot water demand re-circulation systems.
  • New, innovative practices are available for additional points, including:
    • Grid-interactive electric thermal storage systems
    • Utility/energy provider automatic demand response systems
    • Electrical vehicle charging stations

Stay tuned for next week’s post on the updates to the Water Efficiency category, the fourth category involved in the certification of single-family and multifamily homes.

Download the standard for free or purchase a hard copy. To learn more about certifying your project, visit the Home Innovation Research Lab.

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